Comparison of ethanol concentrations in venous blood and end-expired breath during a controlled drinking study

Concentration-time profiles of ethanol were determined for venous whole blood and end-expired breath during a controlled drinking experiment in which healthy men (n=9) and women (n=9) drank 0.40-0.65 g ethanol per kg body weight in 20-30 min. Specimens of blood and breath were obtained for analysis of ethanol starting at 50-60 min post-dosing and then every 30-60 min for 3-6 h. This protocol furnished 130 blood-breath pairs for statistical evaluation. Blood-ethanol concentration (BAC, mg/g) was determined by headspace gas chromatography and breath-ethanol concentration (BrAC, mg/2l) was determined with a quantitative infrared analyzer (Intoxilyzer 5000S), which is the instrument currently used in Sweden for legal purposes. In 18 instances the Intoxilyzer 5000S gave readings of 0.00 mg/2l whereas the actual BAC was 0.08 mg/g on average (range 0.04-0.15 mg/g). The remaining 112 blood- and breath-alcohol measurements were highly correlated (r=0.97) and the regression relationship was BAC=0.10+0.91BrAC and the residual standard deviation (S.D.) was 0.042 mg/g (8.4%). The slope (0.91+/-0.0217) differed significantly from unity being 9% low and the intercept (0.10+/-0.0101) deviated from zero (t=10.2, P<0.001), indicating the presence of both proportional and constant bias, respectively. The mean bias (BAC - BrAC) was 0.068 mg/g and the 95% limits of agreement were -0.021 and 0.156 mg/g. The average BAC/BrAC ratio was 2448+/-540 (+/-S.D.) with a median of 2351 and 2.5th and 97.5th percentiles of 1836 and 4082. We found no significant gender-related differences in BAC/BrAC ratios, being 2553+/-576 for men and 2417+/-494 for women (t=1.34, P>0.05). The mean rate of ethanol disappearance from blood was 0.157+/-0.021 mg/(g per hour), which was very close to the elimination rate from breath of 0.161+/-0.021 mg/(2l per hour) (P>0.05). Breath-test results obtained with Intoxilyzer 5000S (mg/2l) were generally less than the coexisting concentrations of ethanol in venous blood (mg/g), which gives an advantage to the suspect who provides breath compared with blood in cases close to a threshold alcohol limit.     

Postmortem blood and vitreous humor ethanol concentrations in a victim of a fatal motor vehicle crash

A 20-year-old male was found on the passenger side of a small car after a collision with a semi-trailer truck. Postmortem blood, collected from the chest cavity, and vitreous humor samples were collected following harvesting of the heart and bones. Gas chromatographic analysis revealed a blood ethanol concentration of 0.32 g/dL and a vitreous humor ethanol concentration of 0.09 g/dL. The stomach was intact and full of fluid and food, but its contents were not collected. Possible explanations for the large difference between the two results include diffusion of ethanol from the stomach into the chest cavity, contamination of the blood sample prior to collection, and ingestion of a large quantity of ethanol shortly before death. This case demonstrates the importance of proper quality assurance procedures in collecting postmortem specimens and of collecting a vitreous humor sample for ethanol analysis in postmortem toxicology cases.     

Relationships between concentrations of cocaine and its hydrolysates in peripheral blood, heart blood, vitreous humor and urine

Cocaine is known to degrade in vivo and in vitro by several hydrolytic mechanisms. A previous study found that the initial amount of cocaine added to plasma could be accounted for by summing the molar concentrations of cocaine's hydrolysis products and the cocaine remaining after hydrolysis. The present study was undertaken to investigate whether or not relationships might exist between such molar concentration sums for different postmortem bodily fluids. Determinations of cocaine, benzoylecgonine, ecgonine methyl ester, and ecgonine were performed using liquid chromatography/mass spectrometry (LC/MS/MS) with heart blood, femoral blood, vitreous humor (VH), and urine (UR). The results demonstrate a strong correlation between blood and VH concentrations (correlation coefficients of 0.88-0.94), weak correlation between the UR and blood concentrations (correlation coefficients of 0.61-0.64), and weak correlation between UR and VH concentrations (correlation coefficient of 0.59). The results demonstrate that ecgonine is a significant hydrolysate with concentrations on the same order of magnitude as benzoylecgonine. The results are consistent with rapid distribution of the parent drug and its hydrolysates in the blood and VH. The strong correlation between the blood and VH demonstrates that VH is an important medium for toxicology testing when attempting to make a determination of cocaine intoxication.     

Estimation of ethanol concentrations in biological media. Comparison of alkylnitrite and direct vapor-phase methods

Ethanol assays in the blood, saliva and urine were made according to two methods: alkylnitrite gas-liquid chromatography and direct vapor-phase method without thermostating. N-propanol was used as an internal standard. For saliva and urine the methods produced similar results. For blood, the direct vapor-phase method detected significantly lower level of ethanol compared to alkylnitrite one (p = 0.001). 24-h storage of the samples in refrigerator does not deviate the results. Recommendations are provided for most effective usage of each method.     

Postmortem blood free and total morphine concentrations in medical examiner cases

This purpose of this study was to determine the relationships between postmortem free morphine and total morphine levels in a large series of medical examiner morphine and heroin related deaths. Free morphine, total morphine, and 6-monoacetylmorphine (6-MAM) concentrations were measured by gas chromatography-mass spectrometry (GC-MS) in 87 medical examiner cases over 20 months. The mean total morphine concentration, mean free morphine concentration, and mean percent free morphine for all cases were: 2.3 mg/L (SD 5.2 mg/L), 0.5 mg/L (SD 1.6 mg/L), and 19.4% (SD 22.8%); respectively. Regression analyses showed weak correlations between total and free morphine concentrations over the entire concentration range (0 to 36.6 m/L, r = 0.603, n = 91) and over a subset concentration range of 0 to 1.0 mg/L (r = 0.369, n = 54). Twenty-three out of 56 (41%) tested positive for 6-MAM, indicative heroin abuse cases. Lower total and free morphine concentrations and a higher percent free morphine were found in individuals with detectable 6-MAM. Comparing blood concentrations for cases with and without detectable 6-MAM demonstrated mean total morphine concentrations of 0.9 mg/L versus 2.1 mg/L (p = 0.05), mean free morphine concentrations of 0.3 mg/L versus 0.4 mg/L (p = 0.21), and mean percent free morphine of 34.7% versus 13.7% (p < 0.003), respectively. Our findings demonstrate higher free to total morphine ratios in individuals with detectable 6-MAM than in individuals without 6-MAM. The database established in this study may assist medical examiners in the evaluation of postmortem blood opiates regarding the cause of death in opiate related ingestion cases.     

Classification of digoxin concentrations in blood and tissues in cases under suspicion of poisoning

The clarification of a suspicion of poisoning at all times poses a problem to the forensic toxicologist, when a narrow margin of therapeutic safety and a low dosage coincide as in cases of digoxin poisoning. Statistical methods may serve as an aid. The post mortem digoxin concentration in the tissues of heart, kidney, liver and in blood of 45 patients who had received therapeutic daily doses and of 13 cases of fatal poisoning are compared. After logarithmic transformation of the individual concentration values a two modal distribution is obtained. There is one concentration calculated with equal probability of being classified to "therapeutic or toxic", as well as the probability of observing the "critical" concentrations of 400 ng digoxin/g cardiac tissue, 500 ng/g kidney and 250 ng/g liver after therapeutic dosing. Using the discriminant analysis each of the cases clearly falls into one of the two collectives "therapeutic" and "toxic", when taken as a separate observation. Concentration data of fatal poisonings taken from the literature are as successfully classified as the analytical results of some exhumed bodies under suspicion but not poisoned. As expected the power of discrimination increases with the number of parameters. Because of the relatively slow body distribution of digoxin the blood taken from peripheral vessels is of most important evidence.     

Ethyl glucuronide concentrations in two successive urinary voids from drinking drivers: relationship to creatinine content and blood and urine ethanol concentrations

The concentrations of alcohol in blood (BAC) and two successive urine voids (UAC) from 100 drunk drivers were compared with the concentration of ethyl glucuronide (EtG), a minor metabolite of ethanol in urine, and the urinary creatinine content as an indicator of dilution. The subjects consisted of 87 men with mean age 42.2+/-14.2 years (+/-standard deviation, S.D.) and 13 women with mean age 42.5+/-14.4 years. Ethanol was measured in blood and urine by headspace gas chromatography (GC) and EtG was determined in urine by liquid chromatography-mass spectrometry (LC-MS). The mean UAC was 2.53+/-1.15g/l for first void compared with 2.35+/-1.17g/l for second void, decreasing by 0.18+/-0.24g/l on average (P<0.001 in paired t-test). The ratios of UAC/BAC were 1.35+/-0.25 for first void and 1.20+/-0.16 for second void and the difference of 0.15+/-0.27 was statistically significant (P<0.001). The UAC/BAC ratio was not correlated with creatinine content of the urine specimens, whereas the concentration of urinary EtG was positively correlated with creatinine (r=0.64 for first void and r=0.62 for second void). The UAC was not correlated with urinary EtG directly (r=-0.03 for first void and r=0.08 for second void) but after adjusting for the relative dilution of the specimens (EtG/creatinine ratio) statistically significant positive correlations were obtained (r=0.58 for first void and r=0.57 for second void). The dilution of the urine, as reflected in creatinine content, is important to consider when EtG measurements are interpreted. The excretion of EtG in urine, like glucuronide conjugates of other drugs, is influenced by diuresis. EtG represents a sensitive and specific marker of acute alcohol ingestion with applications in clinical and forensic medicine.     

Blood, bone marrow and eye fluid ethanol concentrations in putrefied rabbits

The effect of putrefaction on postmortem blood, bone marrow and eye fluid ethanol levels was evaluated in rabbits. Control and dosed animals were sacrificed and stored at either room temperature (approx. 19 degrees C) or cold temperature (approx. 3.5 degrees C) for as long as 28 days. Control animals stored at room temperature showed ethanol levels in the bone marrow that peaked at 7 days after sacrifice, followed by decreases to a nondetectable level at 21 days. Overall decreases were demonstrated in bone marrow of dosed rabbits stored at room temperature for all postmortem intervals. The control animals stored at low temperature showed no ethanol in the bone marrow and blood until 21 days after sacrifice. Dosed rabbits stored at low temperature showed no significant changes in blood and marrow ethanol until 21 days after sacrifice.     

Autobrewing revisited: endogenous concentrations of blood ethanol in residents of the United Arab Emirates.

Endogenous ethanol concentrations in blood were determined by sensitive headspace gas chromatography/mass spectrometry in 1557 residents of the United Arab Emirates. The subjects were from 13 nationalities, of both sexes and of different age groups. There was no significant difference in blood ethanol concentration between nationalities or between sexes within and between nationalities. The data was pooled and the overall median, minimum, maximum, 25% percentile and 75% percentile were 0.04, 0.00, 3.52, 0.01 and 0.09 mg/dl respectively. The values of blood ethanol concentration as reported in this study indicate that they are far too low to have any forensic significance.     

High urine ethanol and negative blood and vitreous ethanol in a diabetic woman: a case report, retrospective case survey, and review of the literature

Several studies have shown that ethanol can be produced in urine infected with yeast or bacteria in vitro. We present the unusual case of a diabetic woman in whom ethanol was produced in her urine in vivo. The decedent was a 19-year-old woman who was noncompliant with her diabetes treatment. She presented to a local hospital in severe diabetic ketoacidosis and died shortly thereafter. Upon arrival at the hospital, a blood glucose of 553 mg/dL was detected. A urinalysis was positive for ketones (> 80 mg/dL), glucose (> 1000 mg/dL), and large budding yeast forms. A drug screen performed on the urine was positive for ethanol. At the coroner/medical examiner office, an autopsy was negative for significant anatomic findings. Toxicology analysis revealed a urine ethanol level 0.32 g/dL, although no ethanol was detected in blood or vitreous samples. A urine gram stain and culture identified Candida glabrata. A retrospective case review of all deaths related to diabetes examined at the coroner/medical examiner office from 1986 to 2003 did not reveal other cases with similar findings. This case of a noncompliant, juvenile-diabetic woman illustrates a rare finding of apparent in vivo glucose fermentation by C. glabrata to form ethanol in the urine. This case also highlights a potential difficulty in toxicologic analysis and interpretation using urine only.     

Tolerance at high blood alcohol concentrations: a study of 110 cases and review of the literature

One hundred ten consecutive alcoholics who voluntarily entered a detoxification center were studied to determine their ability to perform certain designated functions (a) while under the influence of alcohol at admission and (b) four days later, after they had undergone detoxification. Their blood alcohol concentrations (BACs) within an hour of admission were determined by using the DuPont Automated Clinical Analyzer (ACA), following standard procedures. The results of the tests performed by these subjects were then studied to ascertain the level of psychomotor impairment in alcoholics at elevated BACs. The results were broken down by age, sex, race, and BAC. The findings indicate that alcoholics develop an increased tolerance to alcohol at BACs, which are extremely high, including levels generally considered to be potentially fatal.     

The unreliability of using a urine ethanol concentration to predict a blood ethanol concentration

Of approximately 5,000 forensic cases with a positive ethanol result, over 1,000 were available in which both blood and urine were present for comparison of ethanol content. Data were examined for calculation of the urine to blood ethanol concentration ratio, with the intent of evaluating the validity of predicting a blood ethanol level given a urine ethanol level. The overall urine to blood ethanol concentration ratio was 1.57:1 with a range of 0.7 to 21.0:1. The extremely wide range of values implies that a large degree of error would be introduced if a mean ratio was used when predicting a blood ethanol level from a urine ethanol level.     

Iatrogenically-related, fatal methotrexate intoxication: a series of four cases

Since the early eighties, the folic antagonist methotrexate (MTX) has been used in long-term treatment of rheumatoid arthritis. Because of the high toxic potential clinical and laboratory controls at regular intervals and patient education in order to avoid misadventure is of overriding importance. We present four cases of fatal MTX intoxication due to medical malpractice from the Tübingen Institute of Forensic Medicine autopsy material, which show the severe consequences of MTX overdose. It becomes evident that among non-rheumatologists there still is need for information about toxicity and dose limitation in MTX low-dose treatment.     

Sevoflurane concentrations in blood, brain, and lung after sevoflurane-induced death

Sevoflurane concentrations in blood, brain, and lung were measured in an individual apparently dying from sevoflurane inhalation. Sevoflurane is a volatile nonflammable fluorinated methyl isopropyl ether inhaled anesthetic, chemically related to desflurane and isoflurane. The incidence of abuse of sevoflurane is lower than that of other drugs of abuse possibly due to its inaccessibility to the general public and less pleasurable and addicting effects. The dead subject was an anesthetist found prone in bed holding an empty bottle of sevoflurane (Ultane). Serum, urine, and liver were screened for numerous drugs and metabolites using enzyme immunoassays and gas chromatography-mass spectrometry. Analysis did not reveal presence of any drug, including ethanol, other than sevoflurane. Sevoflurane was determined by headspace gas chromatography and revealed concentrations of 15 microg/mL in blood and 130 mg/kg in brain and lung. Autopsy revealed pulmonary edema and frothing in the lung, pathological findings associated with death by sevoflurane or hypoxia. The cause of death was ruled as sevoflurane toxicity and the manner of death as accident.     

Blood Versus bone marrow ethanol concentrations in rabbits and humans

Post-mortem ethanol levels in bone marrow and heart blood were determined in rabbits and humans. The average ratio of blood/femur marrow ethanol in 39 rabbits was 2.10 ± 0.23 with a range of 1.27 – 3.50. In 18 human autopsy cases the average ratio of blood/rib marrow ethanol levels was 2.16 ± 0.32 with a range of 1.65 – 2.94. The average blood/marrow ratios in humans and rabbits were comparable. However, a wider range of ratios was noticed in the rabbit study.     

血液中乙醇保存稳定性研究

目的确定血液中乙醇最佳保存条件,探讨影响血液中乙醇含量稳定性的主要因素。方法对血液保存的温度(-20、4、20℃)、防腐剂(NaF、无防腐剂、Na2O2)、储存容器中空气所占比例(0%、25%、50%)和血醇质量浓度(0.2、0.8、2.0mg/mL)四个因素采用正交试验L9(34)方法分组,样本采用顶空气相色谱法进行测定,测定结果采用方差分析进行讨论。结果在20℃保存且不加入防腐剂的两组样本中血醇浓度变化明显,其余变化不明显。结论血液样本在4℃、储存容器中空气比例为50%和加防腐剂(NaF)的条件下保存,稳定性最佳;四个影响因素中温度为影响血液中乙醇含量稳定性的主要因素。